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| author | Haavard Skinnemoen <haavard.skinnemoen@atmel.com> | 2008-10-23 09:23:08 (GMT) |
|---|---|---|
| committer | Haavard Skinnemoen <haavard.skinnemoen@atmel.com> | 2008-10-23 13:18:33 (GMT) |
| commit | e3f91ca48162c3eb70450314a4d09384fccb92fa (patch) | |
| tree | 07da27300068cb64fcc7e79bcdb502359b668ff7 /arch/avr32 | |
| parent | 6090065663ba5daab82d116d3040dc924e8cf79f (diff) | |
| download | linux-e3f91ca48162c3eb70450314a4d09384fccb92fa.tar.xz | |
avr32: Scale loops_per_jiffy when cpu frequency changes
The loops_per_jiffy variable isn't updated when cpufreq changes the CPU
frequency. This could cause udelay() and friends to produce wrong
delays.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Diffstat (limited to 'arch/avr32')
| -rw-r--r-- | arch/avr32/mach-at32ap/cpufreq.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/avr32/mach-at32ap/cpufreq.c b/arch/avr32/mach-at32ap/cpufreq.c index d84efe4..024c586 100644 --- a/arch/avr32/mach-at32ap/cpufreq.c +++ b/arch/avr32/mach-at32ap/cpufreq.c @@ -40,6 +40,9 @@ static unsigned int at32_get_speed(unsigned int cpu) return (unsigned int)((clk_get_rate(cpuclk) + 500) / 1000); } +static unsigned int ref_freq; +static unsigned long loops_per_jiffy_ref; + static int at32_set_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation) @@ -61,8 +64,19 @@ static int at32_set_target(struct cpufreq_policy *policy, freqs.cpu = 0; freqs.flags = 0; + if (!ref_freq) { + ref_freq = freqs.old; + loops_per_jiffy_ref = boot_cpu_data.loops_per_jiffy; + } + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + if (freqs.old < freqs.new) + boot_cpu_data.loops_per_jiffy = cpufreq_scale( + loops_per_jiffy_ref, ref_freq, freqs.new); clk_set_rate(cpuclk, freq); + if (freqs.new < freqs.old) + boot_cpu_data.loops_per_jiffy = cpufreq_scale( + loops_per_jiffy_ref, ref_freq, freqs.new); cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); pr_debug("cpufreq: set frequency %lu Hz\n", freq); |